Based on the capistrano/rails gem: https://github.com/capistrano/rails/blob/master/lib/capistrano/tasks/migrations.rake

namespace :somenamespace do  task :runrake do    on roles(:all) do      within release_path do        with rails_env: fetch(:rails_env) do          execute :rake, ask :task        end      end     end  endend

You can create a corresponding capistrano task to run a specific rake task like that:

namespace :guests do  desc 'Remove guest users older than 7 days'  task :clean do    on roles(:app) do      within release_path do        with rails_env: fetch(:rails_env) do          execute :rake, 'guests:delete_old_guest_users'        end      end    end  endend

So I have been working on this. it seams to work well. However you need a formater to really take advantage of the code.

If you don't want to use a formatter just set the log level to to debug mode.

SSHKit.config.output_verbosity = Logger::DEBUG

Cap Stuff

namespace :invoke do  desc 'Run a bash task on a remote server. cap environment invoke:bash[\'ls -la\'] '  task :bash, :execute do |_task, args|    on primary :app do      within deploy_to do        with rails_env: fetch(:rails_env) do          SSHKit.config.format = :supersimple          execute args[:execute]        end      end    end  end  desc 'Run a rake task on a remote server. cap environment invoke:rake[\'db:migrate\'] '  task :rake, :task do |_task, args|    on primary :app do      within current_path do        with rails_env: fetch(:rails_env) do          SSHKit.config.format = :supersimple          rake args[:task]        end      end    end  endend

This is the formatter I built to work with the code above. It is based off the :textsimple built into the sshkit but it is not a bad way to invoke custom tasks. Oh this many not works with the newest version of sshkit gem. I know it works with 1.7.1. I say this because the master branch has changed the SSHKit::Command methods that are available.

module SSHKit  module Formatter    class SuperSimple < SSHKit::Formatter::Abstract      def write(obj)        case obj        when SSHKit::Command    then write_command(obj)        when SSHKit::LogMessage then write_log_message(obj)        end      end      alias :<< :write      private      def write_command(command)        unless command.started? && SSHKit.config.output_verbosity == Logger::DEBUG          original_output << "Running #{String(command)} #{command.host.user ? "as #{command.host.user}@" : "on "}#{command.host}\n"          if SSHKit.config.output_verbosity == Logger::DEBUG            original_output << "Command: #{command.to_command}" + "\n"          end        end        unless command.stdout.empty?          command.stdout.lines.each do |line|            original_output << line            original_output << "\n" unless line[-1] == "\n"          end        end        unless command.stderr.empty?          command.stderr.lines.each do |line|            original_output << line            original_output << "\n" unless line[-1] == "\n"          end        end      end      def write_log_message(log_message)        original_output << log_message.to_s + "\n"      end    end  endend